uv-allign-distribute add-on
The instructions for installing the addon could be clearer.

The releases download page on github has several download options, the easy one is the uv_align_distribute.zip - download this and you can select the zip file after clicking Install Add-on From File... in blenders preferences.



If you download one of the other options or download the whole repo from the project page you get the whole repo and you will need to copy one folder out of it to your addon folder.

After unzipping the full repo download, copy the uv_align_distribute folder, into your addon folder, not the outer folder that will have -master or -3.0 in the name, but the inner folder that will be seen with the docs and tests folders. The best location will be in scripts/addons in your user config location. If you want to, you could copy it into the blender install with the existing addons.